fealty vs loyalty

fealty

noun
  • Fidelity to one's lord or master; the feudal obligation by which the tenant or vassal was bound to be faithful to his lord. 

  • The oath by which this obligation was assumed. 

loyalty

noun
  • Faithfulness or devotion to some person, cause or nation. 

  • The state of being loyal; fidelity. 

How often have the words fealty and loyalty occurred in a corpus of books? (source: Google Ngram Viewer )